Explosive initiator comprising barium styphnate and lead azide



3,234,255 EXPLOSHVE INHTKATOR COMPRISING BUM STYPHNATE AND LEAD AZHDELewis Robert Rothstein, Keith Benner Mullin, and Wayne Eugene Jewsbury,all of Asheviile, N.(1., assignors, by mesne assignments, to NorthropCarolina, Ina, Swannanoa, N.C., a corporation of North Carolina NoDrawing. Filed July 1, 1965, Ser. No. 468,963 2 (Claims. (Cl. 149-23)This invention relates to the initiation of secondary explosives. Itmore particularly relates to an initiator for secondary explosives whichinitiator is at least as insensitive to detonation as the secondaryexplosive being initiated.

A certain class of explosive materials is known as secondary explosives.These include pentaerythritol tetranitrate, tetramethylenetetranitramine, trimethylene trinitramine andtrinitrophenylmethylnitramine. These so-called secondary explosives arequite desirable in that they are not as dangerous to handle as theso-called primary explosives.

One of the problems which has plagued the art in this area is thatsecondary explosives must be detonated by an initiator. Until now, ithas been though necessary to provide an initiator for this system whichis a primary explosive and therefore more dangerous to handle than thesecondary explosive being detonated.

It has now been found that a particular initiator can be provided todetonate secondary explosives, which initiator is no more dangerous tohandle than the secondary explosive to be detonated.

The initiator according to this invention is a mixture of bariumstyphnate and lead azide. It should be noted that lead azide is aprimary explosive which by itself is more dangerous to handle than thesecondary explosives which it will initiate. The mixture then of bariumstyphnate and lead azide has sufiicient explosive power to detonatepentaerythritol te-tranitrate, tetramethylene tetranitramine,trimethylene trinitramine, and trinitrophenyl-methylnitramine, yet is nomore sensitive to shock than the pentaerythritol tetranitrate, etc.,which is being detonated.

In carrying out this invention, it is important to utilize mixtures oflead azide and barium styphnate within the range of 1 part lead azide to1 part barium styphmate to 1 part lead azide to 10 parts bariumstyphnate.

The following examples are given by way of illustration of the instantinvention and are not limiting thereon. Parts and percentages expressedtherein are by weight unless specifically designated to the contrary.

Example I "ice time. The mixture described above (which is the initiatorof the instant invention) was detonated according to the above describedtest by the drop of the 2 kilogram weight from a height of 31centimeters. Pentaerythritol by comparison is detonated fifty percent ofthe time when said 2 kilogram weight is dropped from a height of 17centimeters. It will be noted from comparing these two figures that themixture described above is considerably less shock sensitive than ispentaerythritol.

A column of the mixture described above was detonated adjacent to acolumn of pentaeryt-hirtol and this mixture was found to detonate thepentaerythritol.

Example [I A mixture of one part of lead azide to ten parts bariumstyphnate was made of the two materials together. This mixture of leadazide and barium styphnate was subjected to a drop weight sensitivitytest using type 12 drop hammer tooling. This test comprises dropin-g a 2kilogram weight fro mpredetermined heights of samples of the explosiveand determining the weight at which detonation of the explosive occursfifty percent of the time. The mixture described above (which is theinitiator of the instant invention) was detonated according to the abovedescribed test by the drop of the 2 kilogram weight from a height of 68centimeters. Pentaerythritol by comparison is detonated fifty percent ofthe time when said 2 kilogram weight is dropped from a height of 17centimeters. It will be noted from comparing these two figures that themixture described above is considerably less shock sensitive than ispentaerythritol.

A column of the mixture described above was detonated adjacent to acolumn of pentaery-thirtol and this mixture was found to detonate thepentaerythritol.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing fro-m the spirit of our invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An insensitive explosively detonatable composition for ignitingsecondary explosives comprising between 1 part barium styphnate to 1part lead azide and 10 parts barium styphnate to 1 part lead azide.

2. An intiator composition consisting of a mixture of between 1 partbarium styphnate to 1 part lead azide and 10 parts barium styphnate to 1part lead azide and a secondary explosive selected from the groupconsisting of pentaerythrithol tetranitrate, tetramethylenetetranitramine, trimethylene, trinitramine andtrinitrophenylmethylnitramine.

References Cited by the Examiner FOREIGN PATENTS 687,341 5/1964 Canada.280,249 8/1928 Great Britain.

BENJAMIN R. PADGETT, Acting Primary Examiner.

LEON D. RODSOL, Examiner.

L. A. SEBASTIAN, Assistant Examiner.

1. AN INSENSITIVE EXPLOSIVELY DETONATABLE COMPOSITION FOR IGNITINGSECONARY EXPLOSIVES COMPRISING BETWEEN 1 PART BARIUM STYPHNATE TO 1 PARTLEAD AZIDE AND 10 PARTS BARIUM STYPHNATE TO 1 PART LEAD AZIDE.